Well, the ir-protocol that is used with the xbox remote control sends two different parts of information. First the address that tells xbox that it is supposed to read the signal, and the signal. For the xbox, this address is 5 in decimal form, which translates to 0101 in binary.
Secondly, all IR signals are sent binary. If you can tell the beo5 to use the correct protocol (RCA) then I don't think you will have to worry about this. It all depends on how one programs a beo5. Since I don't own one, I don't know how to program it. :)
Lets say you can choose an address. Then you will have to set this to be 5. If you cannot, then I think you will have to put 5 in front of the command you want to send.
I'm sorry I'm not able to help you more. :/